Factors associated with caregivers’ contribution to self-care in heart failure

Abstract Objective: to analyze the caregiver’s contribution to self-care in heart failure and the predictor variables of this contribution. Method: a cross-sectional descriptive and analytical study, with the participation of 140 dyads (patients and caregivers). The contribution to self-care was assessed using the Caregiver Contribution to Self-Care of Heart Failure Index. Caregivers and patients were interviewed separately to obtain the data. Multiple linear regressions were used to verify predictor variables of caregiver contribution. Results: the mean score for contribution to maintenance self-care was 62.7 (SD=7.1), for management, 62.9 (SD=20.4) and for confidence was 63.3 (SD=22.1). The variables number of patient’s medications, caregiver being related to the patient, social perception of caregiver, health-related quality of life of the patient and caregiver’s confidence in contributing to self-care were predictors of caregiver’s contribution to maintenance or management self-care. Conclusion: the caregiver’s contribution was insufficient. The social support perceived by the caregiver, the type of relationship the caregiver to the patient, the number of medications used by the patient, as well as the caregiver’s confidence in contributing to self-care are variables that should be considered to assess the risk of insufficient contribution of the caregiver.

caregiver relationship influences the willingness for mutual contribution within the dyad.
The caregivers' contribution is considered a process with actions ranging from recommending a particular behavior or replacing that behavior for the patient. One of the assumptions of the theory is that the caregiver contribution is influenced by factors related to the patient, the caregiver, and the relationship between them (11) .
However, there are still few studies that try to verify the caregiver and patient characteristics that influence the caregiver's contribution and little is known about these relationships in samples of Brazilians.
This study aimed to analyze the caregiver's contribution to SC in HF and the predictor variables of this contribution.

Method Design, location and time period
This study was a secondary analysis of data obtained in a cross-sectional, descriptive and analytical study conducted with patients with HF and their respective informal caregivers (dyads). The primary study was has 21 questions about the limitations often associated with the syndrome and how much they prevent patients with HF to live as they would like in the last month. The response options for each question range from zero (no limitation) to five (maximum limitation) in the physical, emotional and other non-dimensional dimensions. The total score is calculated by summing the answers in the 21 items and the scores for each item can range from zero to five points; the overall scale score is from zero to 105 points (15) .
Patients' knowledge about HF was assessed by a questionnaire adapted and validated for Brazil, which has 14 questions with four alternative answers on topics related to HF care, such as alcohol use, use of drugs, weight control, salt consumption, physical activity, reasons for readmission and general information about HF. The instrument generates an overall score of 100%, which is calculated according to the number of correct answers, in which the higher the number of correct answers, the better is the knowledge about HF (16) . indicate how often he/she has each type of support within a five-point Likert scale: 1 ("never"); 2 ("rarely"); 3 ("sometimes"); 4 ("almost always") and 5 ("always").
The overall index is obtained by summing the responses to the 19 items, with higher scores indicating better results regarding social support (18) .
Caregiver strain was obtained by the Caregiver Role Stress Scale that was developed for Brazil and Colombia.
The Brazilian scale has 21 items, with the responses for each item ranging from zero to two. The final score of the scale ranges from zero to 42 and higher scores indicate greater caregiver strain (19) .
Of the 140 dyads, 112 (80%) lived in the same household; of the 140 caregivers, 48.57% were spouses, 24.29% were the patients' daughters, 13.57% were the patients' father or mother, and the others were sisters   (20) .
In the association analyses between the scores of the In order to analyze patient and caregiver variables potentially predictive of caregivers' contribution to SC of patients with HF, multiple linear regression models were built for caregiver contribution to maintenance SC and management SC as outcomes; the variables were defined based on scientific evidence on factors influencing caregiver and patient SC as possible predictors (21)(22) .

Patient confidence for SC and caregiver confidence
in their abilities to contribute to SC were included as possible predictors in the model of caregiver contribution to management SC. There was no evidence of multicollinearity in the predictor variables and generalized variance inflation factor (VIF) of 2 was considered the cutoff point for evidence of multi-collinearity. A significance level of 5% was adopted for all analyses.

Ethical aspects
The project was approved by the Ethics and Research  (23) . Patients and caregivers after being aware of the terms of participation contained in the specific FICT gave their agreement by signing the document.

Results
A total of 140 patients with HF and 140 informal caregivers, indicated by the patients, participated in the study. Table 1 presents demographic and social characteristics of patients and caregivers.

Discussion
The informal caregiver is fundamental for the SC of the person with HF (11,24) , but the knowledge capable of supporting this statement still needs to advance (10) . This cut-off point is the recommended one for interpreting the SCHFI scores (25) and, considering that the CC-SCHFI mirrors the SCHFI, we chose to use it in this context, as it has been used in other studies with this same instrument (21,25) .
Although the caregivers' mean scores were below the cut-off point in SC for maintenance and management and in confidence for SC, they are higher among Brazilian caregivers than among Italian caregivers (21,(26)(27) . In an Italian study, the contribution to the maintenance SC had a mean score of 55.9 (most caregivers did not recommend the patient to monitor body weight or to perform physical activities). In the contribution to the management SC, the mean score was 58.4 (most caregivers reported not to quickly recognize the exacerbation of HF symptoms) and, regarding the caregiver's confidence, the mean score was 56.9, also reflecting low confidence to contribute to the SC of the patient with HF (27) .
The mean scores of patients with HF in this study are similar to those of other Brazilian or foreign studies that, in general, are also below 70 points indicating insufficient SC (8,(28)(29)(30)(31) . The results in Tables 2 and 3 also show that caregivers had higher mean scores than patients in the maintenance SC. In the management SC the same occurs, but the magnitude of the difference is smaller. As for the confidence for the SC, the patients' mean score was similar to the caregivers', but these differences were not statistically analyzed.
In summary, the results discussed so far allow us to state that the studied sample of caregivers, in terms of behaviors contributing to SC, is similar to that of other countries, reiterating the need to recognize, together, the caregiver and the patient with HF as the focus of care offered. SC in HF, as in other chronic conditions, requires hard work that needs to be recognized by the patients themselves (32) and health professionals in their clinical practices.
Despite recent advances in research on SC in chronic conditions, especially in HF, knowledge production in the area reflects fragmented efforts due to the lack of continuity and abundance of descriptive studies (33) .
Therefore, knowing how the problem manifests itself in a given situation is indispensable for the development and evaluation of nursing interventions that encompass the patient and caregiver.
The regression models in Tables 4 and 5  in SC (34) . Modeling for the maintenance SC contribution outcome -that refers to caregiver behaviors that promote patient adherence to treatment and symptom monitoring performed to prevent HF exacerbation (12) -resulted in the identification of three predictor variables: one from the patient; and two from the caregiver himself (Table 4). in the same place could favor the incorporation of the caregiver's contribution behaviors to the maintenance SC to the daily routine, such as reminding the patient to monitor body weight. Interestingly, in another study, the type of relationship was a predictor variable of contribution to management SC and not to maintenance SC (21) . It turns out that in this study (21)  Positive perception of social support, which is defined as an exchange of resources between at least two individuals with the goal of improving the recipient's well-being, has been consistently associated with better caregiver outcomes, including the contribution they make to the SC of people with chronic illnesses, including HF (18,21,(35)(36)(37) . In this research, the caregiver's perception of social support positively influenced their contribution to the patient's maintenance SC and to the management SC. Studies (10,19) point out that caregivers with less social support perceived their caregiving role as less enjoyable and more burdensome than those with more social support.
In another study (37) , conducted to test a model in which caregiver variables affect their contribution to the SC of management, a positive and direct influence of social support was observed in the contribution to the SC of management, but not to that of maintenance.
Comparison of these results is limited because of the differences between the analyses performed. In the present study, the contribution to the maintenance SC as a moderating variable in the relationship between social support and the contribution to the management SC was not tested, which could lead to results similar to those of the aforementioned study (37) . These results confirm that the social support perceived by the caregiver is an important element in his/her contribution to SC and initiatives coming from family members and health professionals that support caregivers in this process can culminate in better SC outcomes.
Caregivers of patients with HF experience different levels of burden and strain (38) . In this study, caregiver role strain was not a predictor of caregiver contribution to SC in HF in any of the models (Tables 4 and 5 the results of such measures (12) . Higher scores on the instrument used for the assessment of patient HRQL in this study indicate worse HRQL (15) . Therefore, the results of the present study indicate that the worse the patient's HRQL, the better the caregiver's contribution to SC management. The progression of the syndrome can generate more impact regarding symptoms on the patient's HRQL and at the same time, require from the caregiver more participation, therefore, more contribution to the SC of patient's management.
In line with other research (27,40) and with the theory adopted in this other study (11) , Caregiver confidence was associated with the contribution to the SC of management.
Caregiver confidence, according to the theory of caregiver contribution to the SC of the patient with HF (11) , is defined as the caregiver's belief in his or her ability to help patients with SC in HF. Confidence reflects self-efficacy regarding one's ability to contribute to SC such as feeling confident about one's own ability to recognize the symptoms of HF in the patient (11) and is theorized to mediate the influence between patient, caregiver and patient-caregiver dyad factors and to contribute to the maintenance and management SC (11) . Some studies have sought to test this aspect of the theory (36) , but, there are still gaps related to this knowledge. to meet the demand (10,41) . It is necessary, therefore, that there are public policies that can provide resources and necessary support to informal caregivers, including them with patients in the center of health care (42) .
One of the limitations of this study is its crosssectional design, which does not allow establishing causal or temporal relationships among the variables. Another limitation is the fact that the sample was composed of users of specialized cardiology services and, therefore, had different characteristics from other populations, limiting the generalization of the results obtained. It is suggested that variables related to the patient-caregiver dyad be considered in other studies on the contribution of the caregiver to the SC of the person with HF, as well as the integration of other outcomes of the person with HF, the caregiver and the patient-caregiver dyad.

Conclusion
The caregiver's contribution to self-care of the person with heart failure in the sample studied was insufficient.
It was observed that the greater number of medications used by the patient, better social support perceived by the caregiver and the caregiver type of relationship to patient were predictors of better contribution of the caregiver to maintenance self-care; whereas, the worse health-related quality of life of the patient, better perception of social support by the caregiver, and greater confidence in their own ability to contribute to self-care of the person with heart failure were predictors of better contribution to management self-care.